Photovoltaic disconnect device for storage integration

ABSTRACT

The present disclosure provides a photovoltaic (PV) disconnect device used in an electrical system. The electrical system includes an energy control system electrically coupled to a utility grid. The electrical system includes a PV power generation system electrically coupled to the energy control system. The electrical system includes an energy storage system electrically coupled to the energy control system. The PV disconnect device is electrically coupled to the PV power generation system and the energy control system. The PV disconnect device electrically disconnects the PV power generation system from the energy control system.

CROSS-REFERENCE TO RELATED APPLICATIONS AND INCORPORATION BY REFERENCE

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/027,563, filed on May 20, 2020 and U.S. Provisional PatentApplication No. 63/144,204, filed Feb. 1, 2021, which are incorporatedby reference herein in their entirety for all purposes.

FIELD

The present disclosure relates to photovoltaic disconnect devices. Inparticular, embodiments relate to photovoltaic disconnect devicesintegrated with a storage electrical system providing power backup for ahome or building.

BACKGROUND

Existing photovoltaic (PV) systems integrated with residential homestypically include one or more inverters (e.g., a micro-inverter, astring inverter) to convert the direct current (DC) power generated bythe solar panels into alternating current (AC) power that issynchronized with the utility grid (on-grid). Accordingly, a residentialPV system may generate and distribute electrical power back to theutility grid. To maintain safety, grid interconnection standards requirePV system inverters to detect if there is a grid outage and shutdownoperation of the inverter within a specified time period. This is knownas anti-islanding (AI) detection and protection.

Grid presence is detected and monitored in the solar inverter bymonitoring the AC voltage coming into the inverter from the AC grid. Inaddition to anti-islanding functionality, for solar inverters to operateand produce power, the grid must be within voltage and frequency rangesrequired by regulatory standards, and these standards are typicallyapplied for each phase of a multi-phase AC connection, such as asplit-phase 120/240V connection common in North American homes. Thereare some exceptions that allow solar inverters to operate on asplit-phase AC connection by monitoring only line-to-line (L1-L2)voltages without monitoring the line-to-neutral (L-N) voltages. Theremay be additional regulatory interconnection requirements for solarinverters that do not have L-N monitoring. These requirements couldinclude faster tripping or require additional devices for externaldisconnection of the solar inverter in these abnormal situations.

When some solar inverter types are used with a storage backup system inbackup operation mode (microgrid), there may be interference of the AIdetection of the solar inverter with operation of the storage inverter.In these situations, the AI detection may be turned off in the PVinverter. This allows the PV system to charge the storage system and/orprovide backup power to the residential loads and to avoid faulting fromhigher impedance of the storage micro-grid. AI detection on a PVinverter is typically part of a product certification required forgrid-connected operation. In backup operation, AI is not required.However, if the solar inverter cannot detect L-N voltages, in the eventthat the storage inverter shuts down or becomes disconnected, the AIprotection of the PV inverter may be integral to shutting down the PVsystem quickly because it cannot detect imbalance in the L-N voltages,which could exist without a grid reference (e.g., storage inverter orreal grid).

Recent solar inverters typically have the ability to curtail thegeneration output of PV systems using smart inverter features such asfrequency-watt or volt-watt profiles to match available storage systemcapability. Older (legacy) PV systems typically do not have this abilityand depend other methods to curtail PV production when used in storagesystems. However, some inverters typically cannot curtail PV generationoutput quickly using a frequency-watt scheme due to a slower controlloop. Consequently, if there is a sudden building (e.g., home) load dropor the energy storage system has a slow charging rate that cannot matchincreases in PV power output, the PV system supplies excess power to theresidential electrical system, potentially causing damage to theelectrical system or momentary fault trips due to excess voltage orfrequency conditions.

BRIEF SUMMARY

Accordingly, there is a need, for example, for a PV disconnect devicethat monitors phase L-N voltages and disconnects the PV in an imbalancesituation. In addition, there is a need for a PV disconnect devicehaving the capability to integrate with existing PV power generationsystems that are used to provide backup power to residential homes orbuildings. In addition, there is a need for PV disconnect device thatcan disconnect backup PV power supply to an energy control system with afaster response time by having faster generation and load metering.

In some embodiments, the present disclosure provides an electricalsystem for whole home backup and partial home backup with integratedbreaker spaces and metering. In some embodiments, an electrical systemincludes an energy control system electrically coupled to a utilitygrid. In some embodiments, the electrical system includes a backupphotovoltaic (PV) power generation system electrically coupled to theenergy control system. In some embodiments, the backup PV powergeneration system is configured to generate power and distribute powerto the energy control system. In some embodiments, the electrical systemincludes an energy storage system electrically coupled to the energycontrol system. In some embodiments, the energy storage system has oneor more energy storage units configured to store power distributed bythe backup PV power generation system. In some embodiments, theelectrical system includes a PV disconnect device electrically coupledto backup PV power generation system and the energy control system. Insome embodiments, the PV disconnect device is configured to electricallydisconnect the backup PV power generation system from the energy controlsystem.

In some embodiments, the energy control system includes a backup powerbus electrically coupled to the backup PV power generation system andthe energy storage system, and the PV disconnect device is disposeddownstream of the PV power generation system and upstream of the backuppower bus.

In some embodiments, the energy control system includes a housing and amicrogrid interconnection device (MID) disposed in the housing. In someembodiments, the microgrid interconnection device is configured todisconnect the utility grid from the PV power generation system and theenergy storage system. In some embodiments, the PV disconnect device isdisposed in the housing of the energy control system and incommunication with a controller of the microgrid interconnection device.In some embodiments, the backup PV power generation system comprises afeed circuit configured to distribute power to the energy control systemand a subpanel electrically coupled to the feed circuit. In someembodiments, the PV disconnect device is connected to the subpanel.

In some embodiments, the PV disconnect device includes anelectromechanical relay electrically coupled to the backup PV powergeneration system. In some embodiments, the PV disconnect deviceincludes a solid-state relay or a controllable alternating currentbreaker electrically coupled to the backup PV power generation system.

In some embodiments, the PV disconnect device includes sensor circuitconfigured to measure at least one of voltage and current of the powerdistributed by the backup PV power generation system. In someembodiments, the PV disconnect device includes a controller configuredto process at least one of the AC voltage, frequency, and currentmeasurements from the sensor circuit and selectively actuate electricaldisconnection between the backup PV power generation system and theenergy control system based on the processed voltage and currentmeasurements.

The present disclosure provides a photovoltaic (PV) disconnect devicefor detecting and reacting to backup power faults and allowing energycontrol systems to be compatible with legacy PV power generationsystems. In some embodiments, a PV disconnect device includes a relaycomponent electrically coupled to a feed circuit of a backup PV powergeneration system. In some embodiments, the PV disconnect deviceincludes sensor circuit configured to measure at least one of ACvoltage, frequency, and current across the feed circuit of the PV powergeneration system. In some embodiments, the PV disconnect deviceincludes a connector port electrically coupled to an energy controlsystem. In some embodiments, the connector port is configured tocommunicate with the energy control system via a modbus, controller areanetwork, (CAN), and/or direct control from energy control system.

In some embodiments, the PV disconnect device includes a (e.g., local)controller operatively connected to the relay component, the sensorcircuit, and/or the connector port. In some embodiments, the controlleris configured to receive voltage measurements from the sensor circuitand actuate the relay component. In some embodiments, the controller isconfigured to process the voltage measurements and selectively actuatethe relay component based on the processed voltage measurements.

In some embodiments, the relay component includes a first relayelectrically coupled to a first line/phase of a feed circuit and asecond relay electrically coupled to a second line/phase of the feedcircuit. In some embodiments, the relay component includes a relaydriver configured to energize the first relay and the second relay suchthat the first and second relays electrically disconnect the first andsecond lines/phases of the feed circuit from the energy control system.

In some embodiments, the sensor circuit is configured to measure a firstphase line-to-neutral voltage of the feed circuit and a second phaseline-to-neutral voltage of the feed circuit.

In some embodiments, the processing of at least one of voltage,frequency, and current measurements includes comparing the voltagemeasurements to a first predetermined threshold. In some embodiments,the first predetermined threshold is based on an electrical code. Insome embodiments, the processing of voltage, frequency, and/or currentmeasurements includes determining the power output of the backup PVpower generation system. In some embodiments, the processing of voltage,frequency, and current measurements includes comparing the power outputof the backup PV power generation system to a second predeterminedthreshold. In some embodiments, the second predetermined threshold isbased on a capacity of an energy storage system.

The present disclosure provides methods of controlling a photovoltaic(PV) disconnect device. In some embodiments, the method includes a stepof measuring, by sensor circuit, at least one of AC voltage, frequencyand current distributed along a feed circuit of a backup PV powergeneration system. In some embodiments, the method includes a step ofreceiving, by a controller, one or more voltage, frequency and currentmeasurements from the sensor circuit. In some embodiments, the methodincludes a step of processing, by the controller, the one or morevoltage, frequency and current measurements. In some embodiments, themethod includes a step of actuating, by the controller, a relaycomponent to electrically disconnect the feed circuit of the backup PVpower generation system from an energy control system.

In some embodiments, the step of processing the one or more voltage,frequency, and current measurements includes comparing a voltagemeasurement to a first predetermined threshold. In some embodiments, thefirst predetermined threshold is based on an electrical code. In someembodiments, the measuring of the at least one voltage, frequency, andcurrent along the feed circuit by the sensor circuit includes measuringa first phase line-to-neutral voltage of the feed circuit and a secondphase line-to-neutral voltage of the feed circuit.

In some embodiments, the step of processing the one or more voltage andcurrent measurements includes calculating a current (e.g., momentary)power output of the backup PV power generation system and comparing thecurrent (e.g., momentary) power output to a second predeterminedthreshold. In some embodiments, the second predetermined threshold isbased on at least one of a storage capacity of an energy storage systemelectrically coupled to the backup PV power generation system and a loadcapacity of back-up loads electrically coupled to the feed circuit ofthe backup PV power generation system.

In some embodiments, the relay component includes a first relayelectrically coupled to a first line/phase of the feed circuit and asecond relay electrically coupled to a second line/phase of the feedcircuit. In some embodiments, the actuating by the controller includestransmitting a first drive signal to the first relay and a second drivesignal to the second relay or same signal to both.

In some embodiments, an electrical system includes a backup PV powergeneration system configured to generate and supply power. In someembodiments, the electrical system includes an energy storage systemconfigured to store power supplied by the backup PV power generationsystem. In some embodiments, the electrical system includes an energycontrol system. In some embodiments, the energy control system has amicrogrid interconnection device electrically coupled to the backup PVpower generation system, the energy storage system, at least one backupload, and a utility grid. In some embodiments, the energy control systemhas a controller in communication with the microgrid interconnectiondevice and configured to monitor electronic data of the electricalsystem. In some embodiments, the electrical system has a PV disconnectdevice in communication with the controller and configured toelectrically disconnect the backup PV power generation system from themicrogrid interconnection device. In some embodiments, the controller isconfigured to detect a power deviation event based on the monitoredelectronic data. In some embodiments, when detecting the power deviationevent, the controller actuates the PV disconnect device to disconnectthe backup PV power generation system from the microgrid interconnectiondevice.

In some embodiments, the electronic data includes a power output of thebackup PV power generation system, an available storage capacity of theenergy storage system, and a current load demand by the at least onebackup load.

In some embodiments, the power deviation event includes when themonitored power output of the backup PV power generation system isgreater than the available storage capacity of the energy storagesystem.

In some embodiments, the power deviation event includes when the loaddemand by the at least one backup load decreases below a threshold valuewithin a set time period.

In some embodiments, electronic data includes an operating status of theutility grid electrically coupled to the microgrid interconnectiondevice, and the power deviation event includes when the operating statusindicates a power outage of the utility grid.

In some embodiments, after disconnecting the backup PV power generationsystem from the microgrid interconnection device, the controller isconfigured to keep the PV disconnect device in an open state for apredetermined time period. In some embodiments, the predetermined timeperiod is based on an algorithm or a lookup table.

In some embodiments, an electrical system includes a backup photovoltaic(PV) power generation system having at least one PV panel arrayconfigured to generate and supply power. In some embodiments, theelectrical system includes an energy control system. In someembodiments, the energy control system has a microgrid interconnectiondevice having a backup side electrically coupled to the backup PV powergeneration system and at least one backup load and a non-backup sideelectrically coupled to a utility grid. In some embodiments, the energycontrol system has a controller in communication with the microgridinterconnection device and configured to monitor electronic data of theelectrical system. In some embodiments, the electrical system includes afirst PV disconnect device disposed downstream of at least one PV panelarray of the backup PV power generation system and upstream of thebackup side of the microgrid interconnection device. In someembodiments, the first PV disconnect device is in communication with thecontroller and configured to electrically disconnect the at least one PVpanel array of the backup PV power generation system from the microgridinterconnection device.

In some embodiments, the energy control system includes a PVinterconnection electrically coupled to at least one PV panel array ofthe backup PV power generation system. In some embodiments, the energycontrol system includes a backup power bus electrically coupled to thePV interconnection and the microgrid interconnection device. In someembodiments, the energy control system includes a housing covering themicrogrid interconnection device, the backup bower bus, and the PVinterconnection.

In some embodiments, the first PV disconnect device is electricallycoupled to the backup power bus and disposed inside the housing. In someembodiments, the first PV disconnect device is electrically coupled tothe backup power bus and disposed outside the housing. In someembodiments, the first PV disconnect device is electrically coupled tothe PV interconnection and disposed outside the housing of the energycontrol system. In some embodiments, the first PV disconnect deviceincludes a housing separated from the housing of the energy controlsystem.

In some embodiments, the electrical system includes a second PVdisconnect device disposed downstream of at least one second PV panelarray of the backup PV power generation system and upstream of thebackup side of the microgrid interconnection device. In someembodiments, the second PV disconnect device is configured toelectrically disconnect the at least one second PV panel array from themicrogrid interconnection device.

In some embodiments, the first PV disconnect device is electricallycoupled to the backup power bus and disposed inside the housing, and thesecond PV disconnect device is electrically coupled to the backup powerbus and disposed outside the housing.

In some embodiments, the electrical system includes a non-backup PVpower generation system having at least one PV panel array configured togenerate and supply power to the non-backup side of the microgridinterconnection device. In some embodiments, the electrical systemfurther includes a second PV disconnect device disposed downstream of atleast one PV panel array of the non-backup PV power generation systemand upstream of the non-backup side of the microgrid interconnectiondevice.

In some embodiments, the present disclosure provides a method forcontrolling an electrical system having a backup PV power generationsystem, an energy storage system, and an energy control system, theenergy control system electrically coupled to the PV power generationsystem, the energy storage system, a plurality of loads, and a utilitygrid. In some embodiments, the method includes a step of monitoringelectronic data from the electrical system. In some embodiments, themethod includes a step of determining whether the monitored electronicdata indicates a power deviation event. In some embodiments, the methodincludes a step of opening a PV disconnect device to electricallydisconnect the backup PV power generation system from a microgridinterconnection device of the energy control system.

In some embodiments, the step of determining whether the monitoredelectronic data indicates a power deviation event further includesdetecting when an operating status of the utility grid indicates a poweroutage. In some embodiments, the step of determining whether themonitored electronic data indicates a power deviation event furtherincludes comparing a frequency of the power supplied by the backup PVpower generation system to a setpoint frequency.

In some embodiments, the present disclosure provides a method forcontrolling an electrical system having a backup PV power generationsystem, an energy storage system, and an energy control system, theenergy control system electrically coupled to the PV power generationsystem, the energy storage system, a plurality of loads, and a utilitygrid. In some embodiments, the method includes a step of receivingelectronic data indicating a power output of backup PV power generationsystem. In some embodiments, the method includes a step of determiningwhether the power output of backup PV power generation system exceeds aPV output threshold. In some embodiments, the method includes a step ofoperating a PV disconnect device in a feedforward control mode whenpower output is above the PV output threshold and in a dynamic controlmode when power output is below the PV output threshold. In someembodiments, operating the PV disconnect device in the feedforwardcontrol mode includes using a lookup table stored in a memory of acontroller. In some embodiments, operating the PV disconnect device inthe dynamic control mode includes using an algorithm stored in thememory of a controller.

In some embodiments, the algorithm includes using electronic datarelated to backup PV power generation system, the energy storage system,the plurality of loads, and/or the utility grid. In some embodiments,the lookup table includes field (e.g., column or row) listing valuescorresponding to PV power output of backup PV power generation system.In some embodiments, the lookup table includes a field listing valuescorresponding to the time of day. In some embodiments, the lookup tableincludes a field listing values corresponding to a predetermined timeperiod for keeping PV disconnect device in a closed state or open state.

In some embodiments, the present disclosure provides an electricalsystem. In some embodiments, the electrical system includes an energycontrol system electrically coupled to a utility grid. In someembodiments, the electrical system includes a backup photovoltaic (PV)power generation system electrically coupled to the energy controlsystem. In some embodiments, the backup PV power generation system isconfigured to generate and supply power. In some embodiments, theelectrical system includes an energy storage system electrically coupledto the energy control system. In some embodiments, the energy storagesystem has one or more energy storage units configured to store powersupplied by the backup PV power generation system. In some embodiments,the electrical system includes a PV disconnect device electricallycoupled to backup PV power generation system and the energy controlsystem. In some embodiments, the PV disconnect device is configured toelectrically disconnect the backup PV power generation system from theenergy control system.

In some embodiments, the energy control system includes a backup powerbus electrically coupled to the backup PV power generation system andthe energy storage system, and the PV disconnect device is disposeddownstream of the PV power generation system and upstream of the backuppower bus.

In some embodiments, the energy control system includes a housing and amicrogrid interconnection device disposed in the housing. In someembodiments, the microgrid interconnection device is configured todisconnect the utility grid from the PV power generation system and theenergy storage system. In some embodiments, the PV disconnect device isdisposed in the housing of the energy control system and incommunication with a controller of the microgrid interconnection device.

In some embodiments, the energy control system has a microgridinterconnection device electrically coupled to the backup PV powergeneration system, the energy storage system, at least one backup load,and a utility grid. In some embodiments, the energy control system has acontroller in communication with the microgrid interconnection deviceand the PV disconnect device. In some embodiments, the controller isconfigured to monitor electronic data of the electrical system. In someembodiments, the controller is configured to detect a power deviationevent based on the monitored electronic data. In some embodiments, whendetecting the power deviation event, the controller actuates the PVdisconnect device to disconnect the backup PV power generation systemfrom the microgrid interconnection device.

In some embodiments, the electronic data includes a power output of thebackup PV power generation system, an available storage capacity of theenergy storage system, and/or a current load demand by the at least onebackup load. In some embodiments, the power deviation event includeswhen the monitored power output of the backup PV power generation systemis greater than the available storage capacity of the energy storagesystem. In some embodiments, the power deviation event includes when theload demand by the at least one backup load decreases below a thresholdvalue within a set time period. In some embodiments, the electronic dataincludes an operating status of the utility grid electrically coupled tothe microgrid interconnection device, and the power deviation eventincludes when the operating status indicates a power outage of theutility grid. In some embodiments, the electronic data includes afrequency of the power supplied by the backup PV power generationsystem, and the power deviation event includes when the monitoredfrequency of the power supplied by the backup PV power generation systemrises above a setpoint frequency more than a predetermined number oftimes within a predetermined time period. In some embodiments, afterdisconnecting the backup PV power generation system from the microgridinterconnection device, the controller is configured to keep the PVdisconnect device in an open state for a predetermined time period. Insome embodiments, the predetermined time period is based on an algorithmor a lookup table. In some embodiments, the PV disconnect deviceincludes at least one of an electromechanical relay, a solid-staterelay, and a controllable alternating current breaker electricallycoupled to the backup PV power generation system.

The present disclosure provides a photovoltaic (PV) disconnect devicefor detecting and reacting to backup power faults and allowing energycontrol systems to be compatible with legacy PV power generationsystems. In some embodiments, a PV disconnect device includes a relaycomponent electrically coupled to a feed circuit of a backup PV powergeneration system. In some embodiments, the PV disconnect deviceincludes sensor circuit configured to measure at least one of ACvoltage, frequency, and current across the feed circuit of the backup PVpower generation system. In some embodiments, the PV disconnect deviceincludes a connector port electrically coupled to an energy controlsystem. In some embodiments, the PV disconnect device includes acontroller operatively coupled to the relay component, the sensorcircuit, and the connector port. In some embodiments, the controller isconfigured to receive voltage, current, and/or frequency measurementsfrom the sensor circuit and actuate the relay component. In someembodiments, the controller is configured to process the voltage,current, and frequency measurements and selectively actuate the relaycomponent based on the processed voltage, current, and frequencymeasurements.

In some embodiments, the relay component includes a first relayelectrically coupled to a first line of a feed circuit. In someembodiments, the relay component includes a second relay electricallycoupled to a second line of the feed circuit. In some embodiments, therelay component includes a relay driver configured to energize the firstrelay and the second relay such that the first and second relayselectrically disconnect the first and second lines of the feed circuitfrom the energy control system.

In some embodiments, the sensor circuit is configured to measure a firstphase line-to-neutral voltage of the feed circuit and a second phaseline-to-neutral voltage of the feed circuit. In some embodiments, theprocessing of voltage measurements includes comparing the voltagemeasurements to a first predetermined threshold, and wherein the firstpredetermined threshold is based on an electrical code.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate embodiments and, together with thedescription, further serve to explain the principles of the embodimentsand to enable a person skilled in the relevant art(s) to make and usethe embodiments.

FIG. 1 illustrates an electrical system according to an embodiment.

FIG. 2 illustrates a controller architecture according to an embodiment.

FIG. 3 illustrates a PV disconnect device according to an embodiment.

FIG. 4 illustrates a PV disconnect device according to an embodiment.

FIG. 5 illustrates a PV disconnect device according to an embodiment.

FIG. 6 illustrates an energy control system with a PV disconnect devicedisposed in a housing of a controller according to an embodiment.

FIG. 7 illustrates an energy control system with a PV disconnect devicedisposed outside a housing of a controller according to an embodiment.

FIG. 8 illustrates an energy control system with a first PV disconnectdevice disposed on a backup side and a second PV disconnect devicedisposed on a non-backup side according to an embodiment.

FIG. 9 illustrates an energy control system with a first PV disconnectdevice disposed at a first location on a backup side of the energycontrol system and a second PV disconnect device disposed at a secondlocation on the backup side of the energy control system according to anembodiment.

FIG. 10 illustrates a block diagram showing a method of controlling a PVdisconnect device according to an embodiment.

FIG. 11 illustrates a block diagram showing aspects of a computer systemaccording to an embodiment.

FIG. 12 illustrates a lookup table for a feedforward control mode of aPV disconnect device according to an embodiment.

FIG. 13 illustrates a graph showing a PV power output profiled over aday of time according to an embodiment.

FIG. 14 illustrates a block diagram showing a method of controlling a PVdisconnect device according to an embodiment.

The features and advantages of the embodiments will become more apparentfrom the detail description set forth below when taken in conjunctionwith the drawings. A person of ordinary skill in the art will recognizethat the drawings may use different reference numbers for identical,functionally similar, and/or structurally similar elements, and thatdifferent reference numbers do not necessarily indicate distinctembodiments or elements. Likewise, a person of ordinary skill in the artwill recognize that functionalities described with respect to oneelement are equally applicable to functionally similar, and/orstructurally similar elements.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described in detail withreference to embodiments thereof as illustrated in the accompanyingdrawings. References to “one embodiment,” “an embodiment,” “someembodiments,” “certain embodiments,” etc., indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the art to affect such feature, structure,or characteristic in connection with other embodiments whether or notexplicitly described.

The term “about” or “substantially” or “approximately” as used hereinrefer to a considerable degree or extent. When used in conjunction with,for example, an event, circumstance, characteristic, or property, theterm “about” or “substantially” or “approximately” can indicate a valueof a given quantity that varies within, for example, 1-15% of the value(e.g., ±1%, ±2%, ±5%, ±10%, or ±15% of the value), such as accountingfor typical tolerance levels or variability of the embodiments describedherein.

The terms “microgrid,” “backup mode,” and “off-grid” as used hereinrefer to a group of interconnected loads (e.g., plurality of backuploads) and power distribution resources (e.g., backup PV powergeneration system, energy storage system, and energy control system)that function as a single controllable power network independent to theutility grid.

The terms “upstream” and “downstream” as used herein refer to thelocation of a component of the electrical system with respect to thedirection of current or power flow being supplied to the energy controlsystem.

The following examples are illustrative, but not limiting, of thepresent embodiments. Other suitable modifications and adaptations of thevariety of conditions and parameters normally encountered in the field,and which would be apparent to those skilled in the art, are within thespirit and scope of the disclosure.

When PV inverters are used with a storage backup system, there may beinterference of AI detection by the solar inverter during backup mode.In these situations, the AI detection may be disabled in the PV inverterso that PV power generation system may charge the storage system and/orprovide power to the backup loads without interference. Consequently,conventional PV systems may struggle to detect L-N voltage imbalances,thereby posing the risk of spiking residential loads with a voltagesurge. While some PV system inverters have AI mechanisms that arecompatible with micro-grid backup operation, these inverters usuallylack the capability to curtail the generation output of the PV system tomatch available storage capability Thus, there is a need for adisconnect device that can detect and rectify PV fault occurrences witha faster response time, while having the capability to integrate withexisting PV power generation systems that are used to provide backuppower to residential homes or buildings.

More recent PV inverters typically have controlled power generation ofPV systems using a frequency-watt control scheme, in which the PVinverter curtails power output of the PV system when the measuredfrequency rises above a nominal frequency. Since PV inverters cannotcurtail large amounts of PV power output within a short time period,frequency-watt control usually only functions well when the power ratingof the PV system is about equal to or slightly over (e.g., within 10% to20%) the storage capacity of the energy storage system. Accordingly, ifelectrical systems rely on frequency-watt control to curtail PV poweroutput, the available PV power output typically needs to be limited tothe storage capacity of the energy storage system to protect theelectrical system (e.g., a residential electrical system) from receivingexcess power output.

According to embodiments described herein, the PV disconnect device ofthe present disclosure may overcome one or more of these deficiencies,for example, by having a relay component electrically coupled to a feedcircuit of a PV power generation system, sensor circuit configured tomeasure voltage and/or current on both sides of the feed circuit of thebackup PV power generation system, a connector port electrically coupledto an energy control system, and a controller operatively connected tothe relay component, the sensor circuit, and/or the connector port.

Additionally, according to embodiments described herein, the PVdisconnect device of the present disclosure may overcome one or more ofthese deficiencies, for example, by being in communication with thecontroller of the energy control system, in which the controllermonitors electronic data of the electrical system and actuates the PVdisconnect device to open or close based on the monitored electronicdata. Syncing operation of the PV disconnect device with the controllerof the energy control system expedites the generation (e.g., PV poweroutput) and load metering of the PV disconnect device and minimizespotential possibilities of excess PV power output being supplied to theloads, thereby allowing the electrical system to have a higher PV poweroutput while ensuring safe, smooth, and reliable operation of theelectrical system.

FIG. 1 shows an electrical system 100 according to some embodiments. Insome embodiments, electrical system 100 can include an energy controlsystem 110 (e.g., “HUB+”). In some embodiments, electrical system 100can include an energy storage system 150 electrically coupled to energycontrol system 110. In some embodiments, electrical system 100 caninclude a backup photovoltaic (PV) power generation system 160electrically coupled to energy control system 110. In some embodiments,electrical system 100 can include a non-backup PV power generationsystem 190 electrically coupled to energy control system 110. Electricalsystem 100 can include any component or be operated in any way, asdisclosed in U.S. application Ser. No. 16/811,832, filed Mar. 6, 2020,titled “ENERGY CONTROL SYSTEM,” the entirety of which is incorporatedherein by reference.

In some embodiments, electrical system 100 can include a plurality ofelectrical loads 170 electrically coupled to energy control system 110.In the context of the present disclosure, an electrical load can be, forexample, one or more devices or systems that consume electricity. Insome embodiments, the plurality of electrical loads 170 can include allor some of the electrical devices associated with a building. In someembodiments, the plurality of electrical loads 170 can include 240-voltloads. In some embodiments, the plurality of electrical loads 170 caninclude, for example, an electric range/oven, an air conditioner, aheater, a hot water system, a swimming pool pump, and/or a well pump. Insome embodiments, the plurality of electrical loads 170 can include120-volt loads. In some embodiments, the plurality of electrical loads170 can include, for example, power outlets, lighting, networking andautomation systems, a refrigerator, a garbage disposal unit, adishwasher, a washing machine, a septic pump, and/or an irrigationsystem. In some embodiments, the plurality of electrical loads 170 canbe separated into a plurality of backup loads 172 and a plurality ofnon-backup loads 174. In some embodiments, the plurality of backup loads172 include one or more essential loads that continue to receive powerfrom the backup PV power generation system 160 and/or energy storagesystem 150 during a utility power outage, and the plurality ofnon-backup loads 174 include one or more non-essential loads that do notreceive power from the backup PV power generation system 160 and/orenergy storage system 150 during a utility power outage.

In some embodiments, backup PV power generation system 160 can includeone or more power generation arrays 164 (e.g., a photovoltaic panelarray), and each power generation array 164 can include one or morepower generation units (e.g., a photovoltaic panel) configured togenerate power. In some embodiments, backup PV power generation system160 can include one or more PV converters 162 (e.g., a micro-inverter).In some embodiments, PV converter 162 can include any type of components(e.g., an inverter) such that PV converter 162 is configured to convertdirect current (“DC”) to alternating current (“AC”) or vice versa. Insome embodiments, at least one PV converter 162 synchronizes the phaseof the power feed to split-phase AC that is compatible with the utilitygrid. In some embodiments, PV converter 162 can be a part of powergeneration unit. In some embodiments, one, two, three, four, or morepower generation units can be interconnected to a single PV converter162 (e.g., a string inverter). In some embodiments, backup PV powergeneration system 160 includes one or more power optimizers such as, forexample, DC power optimizers. In some embodiments, backup PV powergeneration system 160 can include a feed circuit 168 (e.g., split-phasethree wire) configured to distribute power to the energy control system110.

In some embodiments, non-backup PV power generation system 190 caninclude one or more power generation arrays 194 (e.g., a photovoltaicpanel array), and each power generation array 194 can include one ormore power generation units (e.g., a photovoltaic panel). In someembodiments, non-backup PV power generation system 190 can include oneor more PV converters 192. In some embodiments, PV converter 192 caninclude the features of any one of the converters described herein.

In some embodiments, energy storage system 150 can include one or morestorage units 152. In some embodiments, storage unit 152 can include oneor more batteries 158. In some embodiments, storage unit 152 can includea storage converter 154 configured to adjust a charging rate and/or adischarging rate of the one or more batteries 158.

In some embodiments, energy control system 110 can include a backuppower bus 140, for example, electrically coupled to backup PV powergeneration system 160 via a backup PV interconnection 111, energystorage system 150 via a storage interconnection 112, and the pluralityof backup loads 172 via a backup load interconnection 113.

In some embodiments, energy control system 110 can include a gridinterconnection 116 electrically coupled to a utility grid 184. In someembodiments, grid interconnection 116 can include a non-backup power bus180 and an over-current-protection device 182 (e.g., main service panelwith a main circuit breaker, such as a 200 A circuit breaker)electrically coupled to utility grid 184 so that grid power isdistributed to energy control system 110. In some embodiments, energycontrol system can include a non-backup load interconnection 114electrically coupled to one or more non-backup loads 174 and anon-backup PV interconnection 115 electrically coupled to the non-backupPV power generation system 190.

In the context of the present disclosure, an interconnection includesany suitable electrical structure, such as a power bus, wiring, a panel,etc., configured to establish electrical communication between two setsof circuits. Any one of interconnections 111-116 can include an AC bus,a panel, a sub-panel, a circuit breaker, any type of conductor, or acombination thereof.

In some embodiments, energy control system 110 can include a microgridinterconnection device 120 (e.g., an automatic transfer or disconnectswitch) electrically coupled to backup power bus 140 and non-backuppower bus 180, such that microgrid interconnection device 120 iselectrically coupled to backup PV interconnection 111, storageinterconnection 112, backup load interconnection 113, non-backup loadinterconnection 114, non-backup PV interconnection 115, and/or gridinterconnection 116. In the context of the present disclosure, amicrogrid interconnection device can be, for example, any device orsystem that is configured to automatically connect circuits, disconnectcircuits, and/or switch one or more loads between power sources. In someembodiments, a microgrid interconnection device 120 can include anycombination of switches, relays, and/or circuits to selectively connectand disconnect respective interconnections 111-116 electrically coupledto energy control system 110. In some embodiments, such switches can beautomatic disconnect switches that are configured to automaticallyconnect circuits and/or disconnect circuits. In some embodiments, suchswitches can be transfer switches that are configured to automaticallyswitch one or more loads between power sources.

In some embodiments, microgrid interconnection device 120 can beconfigured to operate in an on-grid mode (e.g., closed), in whichmicrogrid interconnection device 120 electrically connects the backuppower bus 140 to the non-backup power bus 180. In some embodiments, whenoperating under the on-grid mode, microgrid interconnection device 120can be configured to distribute electrical energy received from utilitygrid 184 and non-backup PV power generation system 190 to backup loads172. In some embodiments, when operating under the on-grid mode,microgrid interconnection device 120 can be configured to distributeelectrical energy received from energy storage system 150 and/or backupPV power generation system 160 to non-backup loads 174.

In some embodiments, microgrid interconnection device 120 can beconfigured to operate in a backup mode (e.g., opened), in whichmicrogrid interconnection device 120 electrically disconnects non-backuppower bus 180 from backup power bus 140. In some embodiments, whenoperating under the backup mode, microgrid interconnection device 120can disrupt electrical energy received from non-backup PV powergeneration system 190 from reaching backup loads 172. In someembodiments, when operating under the backup mode, microgridinterconnection device 120 can disrupt electrical communication betweenbackup loads 172 and utility grid 184. In some embodiments, whenoperating under the backup mode, microgrid interconnection device 120can disrupt electrical energy received from energy storage system 150and/or backup PV power generation system 160 from reaching non-backuploads 174.

In some embodiments, energy control system 110 can include a controller122 in communication with microgrid interconnection device 120 andconfigured to control the distribution of electrical energy betweenenergy storage system 150, backup PV power generation system 160, theplurality of electrical loads 170, utility grid 184, and/or non-backupPV power generation system 190. In some embodiments, controller 122 canbe configured to detect the status (e.g., power outage or voltagerestoration) of grid interconnection 116 and switch microgridinterconnection device 120 between the on-grid mode and the backup modebased on the status of grid interconnection 116. If the status of gridinterconnection 116 indicates a power outage, controller 122 can beconfigured to switch microgrid interconnection device 120 to the backupmode. If the status of grid interconnection 116 indicates a voltagerestoration, controller 122 can be configured to switch microgridinterconnection device 120 to the on-grid mode.

FIG. 2 shows a block diagram of an example controller 1500 that can beimplemented as the controller 122 in energy control system 110 accordingto some embodiments. In some embodiments, controller 1500 can include amicrocontroller 1502 having a central-processing-unit (e.g.,programmable system-on-chip controller). In some embodiments, controller1500 can handle microgrid interconnection device coils of 12 volts usingan ALT contactor drive 1504. In some embodiments, controller 1500 cancontrol relays. In some embodiments, controller 1500 can measure currentand voltage (e.g. via current transformer “CT” or Potential transformer“PT”). In some embodiments, controller 1500 can measure the differencesbetween grid power and backup power such as, for example, differences inphase, frequency, voltage, etc. In some embodiments, controller 1500 canhave an internal power supply 1510 (e.g., 5 VDC & 3.3 VDC internal powersupply). In some embodiments, controller 1500 can have external powerinputs 1512 (e.g., 48V to 12 VDC power supply from storage battery). Insome embodiments, controller 1500 can receive power from the electricalgrid, an energy storage system, and/or a power generation system. Insome embodiments, controller 1500 can control microgrid interconnectiondevice coils that need to reverse coil polarity to reset. In someembodiments, controller 1500 can include an auxiliary power input toreceive power from batteries. In some embodiments, controller 1500 caninclude connectors for communicating with and/or controlling themicrogrid interconnection device. In some embodiments, controller 1500can include a “test mode” for simulating a grid outage and/or anemergency system shutdown. In some embodiments, controller 1500 caninclude visual and/or audible alarms, for example, to indicate systemstatus. In some embodiments, controller 1500 can allow a rapid systemshutdown (including remote shutdown) and/or a direct pass-through tosystem inverters for safety. In some embodiments, controller 1500 caninclude generator start relays for continuous backup and/or batteryjump-start relays for “dark-start” situations.

In some embodiments, as shown in FIG. 1 , for example, energy controlsystem 110 can include a PV monitoring system 130 (e.g., PVS6) incommunication with backup PV power generation system 160 and/ornon-backup PV power generation system 190 such that PV monitoring system130 receives electronic data related to backup PV power generationsystem 160 and/or non-backup PV power generation system 190. In someembodiments, PV converter 162 can be configured to send electronic datato and/or receive electronic data from PV monitoring system 130. In someembodiments, PV converter 162 can be configured to receive electronicdata from PV monitoring system 130, and can be configured to changestate (e.g., exporting power or not exporting power, increasing ordecreasing amount of power exporting) based on the electronic datareceived. In some embodiments, PV converter 162 can also be configuredto send electronic data to PV monitoring system 130. For example, insome embodiments, PV converter 162 can be configured to send to PVmonitoring system 130 electronic data relating to the state of backup PVpower generation system 160 (e.g., the amount of power being exported).

In some embodiments, controller 122 can be linked to PV monitoringsystem 130 to receive the electronic data related to backup PV powergeneration system 160 and/or non-backup PV power generation system 190.In some embodiments, controller 122 can control distribution of energybased on the electronic data related to PV power generation system 160and/or non-backup PV power generation system 190.

In some embodiments, energy control system 110 can include a housing 121enclosing controller 122, microgrid interconnection device 120, and/orPV monitoring system 130. In some embodiments, housing 121 can at leastpartially enclose backup power bus 140, non-backup power bus 180, andany one of interconnections 111-116. In some embodiments, PV monitoringsystem 130 can be physically separated from housing 121, for example,linked wirelessly to controller 122 over a local-area-network (e.g.,residential Wi-Fi network). For example, in some embodiments, backup PVpower generation system 160 and PV monitoring system 130 can be disposedon an auxiliary building (e.g., a garage) that is separate from the mainresidential building (e.g., a house).

In some embodiments, energy control system 110 can include a rapidshutdown switch 125 that is configured to rapidly de-energize portionsof electrical system 100 (e.g., portions of energy storage system 150,backup PV power generation system 160, and/or non-backup PV powergeneration system 190). For example, during an emergency (e.g., a fire),persons such as first responders (e.g., firefighters) can use rapidshutdown switch 125 to quickly de-energize portions of energy storagesystem 150, backup PV power generation system 160, and/or non-backup PVpower generation system 190.

In some embodiments, energy control system 110 can include a PVdisconnect device 200 (e.g., a PV relay device) electrically coupled tothe feed circuit 168 of backup PV power generation system 160. In someembodiments, PV disconnect device 200 can be disposed along backup PVinterconnection 111. In some embodiments, PV disconnect device 200 canbe disposed upstream of backup power bus 140 and downstream of ACbreakers 118 for backup PV power generation system 160. In someembodiments, PV disconnect device 200 can be disposed inside housing 121of energy control system 110. In some embodiments, PV disconnect device200 can be disposed outside of housing 121 (e.g., disposed at adownstream subpanel of backup PV power generation system 160). In someembodiments, energy control system 110 can include multiple PVdisconnect devices 200 disposed at different locations in electricalsystem 100 such that each PV disconnect device 200 can electricallydecouple one or more PV power generation arrays 164, 194 from energycontrol system 110. In some embodiments, a controller (e.g., controller122 and/or PV monitoring system 130) of energy control system 110 cancontrol each PV disconnect device 200 independently to partially reducePV power output and/or control all PV disconnect devices 200collectively at the same time to completely reduce PV power output.

In some embodiments, PV disconnect device 200 can be configured tomonitor the power distributed by the feed circuit 168 of backup PV powergeneration system 160. In some embodiments, PV disconnect device 200 canmonitor power distributed by a split-phase feed circuit (e.g.,120V/240V) of backup PV power generation system 160 through measuring:(i) phase one line-to-neutral voltage (e.g., L1-N), (ii) phase twoline-to-neutral voltage, (e.g., L2-N) and/or (iii) line-to-line voltage(e.g., L1-L2) of the feed circuit 168 from backup PV power generationsystem 160. In some embodiments, PV disconnect device 200 can monitorvoltage on both ends of PV disconnect device 200 for any relay welddetection. In some embodiments, the voltage measurements on both sidesof each PV disconnect device 200 is monitored to determine if there is arelay abnormal state with respect to the expected state (e.g., weld orstuck open scenarios).

In some embodiments, PV disconnect device 200 can include any type ofcircuitry component (e.g., a voltmeter, a potential transformer, and/ora current transformer), to measure voltage and/or current across thefeed circuit 168 of backup PV power generation system 160. In someembodiments, PV disconnect device 200 can be in communication withanother controller, such as, for example, controller 122 or PVmonitoring system 130 of energy control system 110, to collect voltagemeasurements and/or power output of feed circuit from backup PV powergeneration system 160.

In some embodiments, PV disconnect device 200 can be configured tomonitor the frequency of the AC distributed by the feed circuit 168 ofbackup PV power generation system 160. In some embodiments, PVdisconnect device 200 can include any type of circuitry component (e.g.,frequency meter, frequency counter, and/or oscilloscope) to measure thefrequency of the AC distributed by the feed circuit 168 of the backup PVpower generation system 160. In some embodiments, PV disconnect device200 can be in communication with another controller, such as, forexample, controller 122 or PV monitoring system 130 of energy controlsystem 110, to collect frequency measurements of feed circuit 168 frombackup PV power generation system 160.

In some embodiments, PV disconnect device 200 can be configured toreceive auxiliary power (e.g., for controller) from an input side and/oran output side. For example, in some embodiments, PV disconnect device200 can be configured to receive power from feed circuit 168 of thebackup PV power generation system 160 and backup power bus 140 of energycontrol system 110. In some embodiments, PV disconnect device 200 can beconfigured to monitor the direction of the current flowing from theinput side to the output side of PV disconnect device 200. In someembodiments, PV disconnect device 200 can be configured to determinewhether the input side is properly connected to feed circuit 168 of thebackup PV power generation system 160 based on the detected direction ofcurrent. For example, if PV disconnect device 200 determines that thedirection of current is being flown from backup power bus 140 to feedcircuit 168, PV disconnect device 200 can indicate an improper wiringwarning to a user.

In some embodiments, PV disconnect device 200 can be configured toprocess the voltage and/or current measurements of the feed circuit 168from the backup PV power generation system 160 (e.g., power output dataof the backup PV power generation system 160). In some embodiments, thePV disconnect device 200 can process the voltage and/or measurementsbased on algorithm(s) that compares the line-to-neutral voltages (e.g.,L1-N voltage, L2-N voltage, root mean square of L1-N and L2-N voltages)to a first threshold. In some embodiments, the PV disconnect device 200can process the voltage and/or measurements based on algorithm(s) thatcompares the line-to-line voltages (e.g., L1-L2 voltage) to a secondthreshold. In some embodiments, the first threshold and/or secondthreshold can be set to comply with state or national codes and productstandards (e.g., UL 1741, NEC 2020). For example, in some embodiments,the first threshold with respect to the line-to-neutral voltages can beset at 120V, and the second threshold with respect to the line-to-linevoltage can be set at 240V. In some embodiments, the first thresholdwith the respect to the line-to-neutral voltages can be set at 120% ofor less (e.g., 120%, 115%, 110%, and/or 105%) than the rating at thepower bus of the service panel (e.g., 120% of the rating at backup powerbus 140 of energy control system 110).

In some embodiments, PV disconnect device 200 can process the voltageand/or current measurements across the feed circuit 168 of backup PVpower generation system 160 to determine the power output (e.g., adynamic or instantaneous power output) of backup PV power generationsystem 160. In some embodiments, PV disconnect device 200 can processthe voltage measurements based on algorithm(s) that compares the poweroutput of backup PV power generation system 160 to an available storagecapacity of energy storage system 150 and/or a load capacity of theplurality of electrical loads 170 (e.g., the load capacity with respectto one or more of backup loads 172 and/or non-backup loads 174). In someembodiments, the available storage capacity corresponds to a differencebetween a total storage capacity and a current state of charge (SoC) ofenergy storage system 150. In some embodiments, PV disconnect device 200can process the voltage measurements based on algorithm(s) that comparesthe backup PV power output to a power threshold. In some embodiments,the power threshold is determined by the storage capacity of energystorage system 150 (e.g., 7.5 kW AC).

In some embodiments, PV disconnect device 200 can be configured toprocess the frequency measurements of the feed circuit 168 from thebackup PV power generation system 160. In some embodiments, PVdisconnect device can process the frequency measurements of the feedcircuit 168 based on algorithm(s) that compares measured frequency to asetpoint frequency (e.g., 60 Hz and/or 50 Hz) to determine if there isan under-frequency event (e.g., when measured frequency drops below thesetpoint frequency) or an over-frequency event (e.g., when measuredfrequency rises above the setpoint frequency). In some embodiments, PVdisconnect device 200 can process the frequency measurements across thefeed circuit 168 of backup PV power generation system 160 to determinethe power output (e.g., a dynamic or instantaneous power output) ofbackup PV power generation system 160.

In some embodiments, PV disconnect device 200 can include a controller(e.g., a microcontroller) to process voltage, current, and/or frequencymeasurements. In some embodiments, PV disconnect device 200 can be incommunication with another controller, such as, for example, controller122 or PV monitoring system 130 of energy control system 110, to processvoltage measurements.

In some embodiments, PV disconnect device 200 can be configured todisrupt the electrical connection between the feed circuit 168 of backupPV power generation system 160 and the backup power bus 140 of energycontrol system 110. In some embodiments, PV disconnect device 200 caninclude an electromechanical relay (e.g., a switch device having a coil,an armature, and contactors) electrically coupled to feed circuit 168 ofPV disconnect device 200 and configured to disrupt the electricalconnection between the feed circuit 168 of backup PV power generationsystem 160 and the backup power bus 140 of energy control system 110. Insome embodiments, PV disconnect device can include a solid-state relay(e.g., semiconductor device having a transistor or integrated-circuit)or controllable AC breaker coupled to feed circuit 168 of PV disconnectdevice 200 and configured to disrupt the electrical connection betweenthe feed circuit 168 of backup PV power generation system 160 and thebackup power bus 140 of energy control system 110.

In some embodiments, controller 122 and/or PV monitoring system 130 ofenergy control system 110 can monitor electronic data of the electricalsystem and actuate PV disconnect device 200 to open and/or close basedon monitored electronic data. In some embodiments, controller 122 or PVmonitoring system 130 can process the electronic data within a set timeperiod (e.g., about 5 milliseconds to about 10 milliseconds) and actuatethe PV disconnect device 200 to open and/or close within a set responseperiod (e.g., 10 milliseconds to 40 milliseconds). By communicating withcontroller 122, PV disconnect device 200 can assume faster generation(e.g., PV power output) and load metering and disconnect backup PV powergeneration system 160 within a faster response time.

In some embodiments, electronic data can be related to, for example,backup PV power generation system 160, energy storage system 150,utility grid 184, the plurality of backup loads 172, and/or non-backuploads 174. In some embodiments, some embodiments, electronic datarelated to backup PV power generation system 160 can include a detectedpower output of backup PV power generation system 160. In someembodiments, electronic data related to backup PV power generationsystem 160 can include a frequency of the power supplied by backup PVpower generation system 160. In some embodiments, electronic datarelated to energy storage system 150 can include an available storagecapacity. In some embodiments, electronic data related to the pluralityof backup loads 172 can include a current (e.g., momentary) backup loaddemand. In some embodiments, electronic data related to the plurality ofnon-backup loads 174 can include a current (e.g., momentary) non-backupload demand. In some embodiments, electronic data related to utilitygrid 184 can include an operating status of utility grid 184electrically coupled to microgrid interconnection device 120 (e.g.,grid-tied or power outage).

In some embodiments, PV disconnect device 200 can be configured todisconnect backup PV power generation system 160 from energy controlsystem 110 when detecting that the measured current exceeds apredetermined threshold current rating. In some embodiments, thepredetermined threshold current rating can range, for example, fromabout 80 A to about 90 A or above. In some embodiments, PV disconnectdevice 200 can be configured to remain open for a set time period (e.g.,about 1 to about 5 hours) after detecting that the measured currentexceeds a predetermined threshold current rating.

In some embodiments, PV disconnect device 200 can convert AC inputtedfrom the feed circuit 168 of the backup PV power generation system 160to low voltage DC that is used to auxiliary power components of PVdisconnect device 200, such as a controller. In some embodiments, PVdisconnect device 200 can reduce the voltage of the AC inputted from thefeed circuit 168 of the backup PV power generation system 160 to aminimal operating voltage. For example, in some embodiments, PVdisconnect device 200 can reduce an input AC at 240V to a DC at 12V/6Vfor bias power supply purposes. In some embodiments, PV disconnectdevice 200 can include any type of circuitry component to convert andreduce power supply from the feed circuit 168 of the backup PV powergeneration system 160.

In some embodiments, PV disconnect device 200 can be configured todisrupt the electrical connection between backup PV power generationsystem 160 and energy control system 110 based on the processing ofvoltage measurements. For example, if PV disconnect device 200determines that the line-to-neutral voltage exceeds a first threshold,PV disconnect device 200 can then disrupt electrical connection betweenbackup PV power generation system 160 and energy control system 110. Insome embodiments, PV disconnect device 200 can be configured to disruptthe electrical connection within a predetermined time period that iscompliant with state or national codes and product standards (e.g., UL1741 and NEC 2020). For example, in some embodiments, the predeterminedtime period for establishing disruption of the electrical connectionbetween backup PV power generation system 160 and energy control system110 can be set at 160 milliseconds or less (e.g., disrupt electricalconnection within 150 milliseconds, within 140 milliseconds).

In some embodiments, PV disconnect device 200 can be configured todisrupt the electrical connection between backup PV power generationsystem 160 and energy control system 110 based on the processing offrequency measurements. For example, if PV disconnect device 200determines that there is an abnormal frequency event, PV disconnectdevice 200 can disrupt electrical connection between backup PV powergeneration system 160 and energy control system 110. In someembodiments, an abnormal frequency event can be defined when themeasured frequency falls below or rises above the setpoint frequency(e.g., 50 and/or 60 Hz) by a predetermined tolerance threshold. In someembodiments, the setpoint frequency can range from about 50 Hz to about70 Hz, such as for example, 59.5 Hz to 60.5 Hz to be compatible with thegrid. In some embodiments, the predetermined tolerance threshold canrange from 0 Hz to about 5 Hz, such as for example, 0.5 Hz to 1.5 Hz. Insome embodiments, an abnormal frequency event can be defined when theoccurrence of the measured frequency rising above or falling below thesetpoint frequency happens more than a predetermined number of timeswithin a set time period. In some embodiments, the predetermined numbercan range from 1 occurrence to 10 occurrences, such as, for example 3occurrences to 5 occurrences. In some embodiments, the predeterminedtime period can range from about 0.1 milliseconds to about 10 minutes,such as, for example, about 10 milliseconds to about 5 seconds.

In some embodiments, after switching to the open state, PV disconnectdevice 200 can be set in the open state for a predetermined time period.In some embodiments, the predetermined time period can be determineddynamically by a control algorithm that continuously evaluates the stateof electrical system 100 based on electronic data related to energystorage system 150, backup PV power generation system 160, the pluralityof electrical loads 170, and/or the utility grid 184. By beingdynamically controlled according to a control algorithm, thepredetermined time period for keeping PV disconnect device 200 in anopen state can be continuously adjusted in response to the detectedconditions of electrical system 100. In some embodiments, thepredetermined time period can be determined by a value set in a lookuptable that is stored in a memory of a controller, such as, for example,controller 122 and/or PV monitoring system 130. By using a lookup tablefor determining the time period, PV disconnect device 200 can remain inan open state according to the value stored in the lookup table.

In some embodiments, PV disconnect device 200 can curtail powerdistributed from on-site generation (e.g., power distributed from backupPV power generation system 160 and/or energy storage system 150) to apredetermined power rating. In some embodiments, the predetermined powerrating can be determined based on local Net Energy Metering (NEM)regulations or National Electrical Code 2020 PCS controls (e.g., ratingsfor electric panels). In some embodiments, PV disconnect device 200 canbe configured to function as a net generation output meter so that thebackup PV power generation system 160 and/or storage system 150 complieswith local NEM regulations.

In some embodiments, PV disconnect device 200 can be compatible with anytype of PV inverter 162 of backup PV power generation system 160, suchas (e.g., an old legacy) PV inverters that lack the capability tocontrol or curtail power output of the backup PV power generation system160 based on smart inverter features such as frequency/watt. In someembodiments, PV disconnect device 200 can allow legacy PV inverters tocomply with modern state or national codes and product standards, and tobe compatible with the latest energy storage systems. For example, insome embodiments, PV disconnect device 200 can disrupt electricalconnection between backup PV power generation system 160 and energycontrol system 110 based on an algorithm that compares backup PV poweroutput to total and/or available storage capacity of energy storagesystem 150. In some embodiments, PV disconnect device 200 can beconfigured to perform all functions as described herein (e.g., monitorvoltage and/or current measurements of feed circuit 168, process thevoltage and/or current measurements, and disrupt electrical connectionbetween backup PV power generation system 160 and energy control system110) while microgrid interconnection device 120 is set in backup mode.

FIG. 3 shows a configuration of PV disconnect device 200 according tosome embodiments. In some embodiments, PV disconnect device 200 caninclude a printed-circuit-board (PCB) 202. In some embodiments, PVdisconnect device 200 can include one or more relay component (e.g.,electromechanical relay, solid-state relay). In some embodiments, therelay component of the PV disconnect device 200 can include a firstrelay 210 disposed on PCB 202 and electrically coupled to a first lineL1 of the feed circuit 168 from backup PV power generation system 160.In some embodiments, the relay component of the PV disconnect device 200can include a second relay 220 disposed on PCB 202 and electricallycoupled to a second line L2 of the feed circuit 168 from backup PV powergeneration system 160. In some embodiments, the relay component of thePV disconnect device 200 can include a relay driver 230 configured toactuate first relay 210 and/or second relay 220. In some embodiments,first and second relays 210, 220 each include a coil and an armature,and relay driver 230 is configured to energize the coils of first andsecond relays 210, 220 to move the armature between open and closedpositions. In some embodiments, the relay component can include twopoles to actuate both the phases (L1 and L2) simultaneously within therelay disconnect device 200.

In some embodiments, PV disconnect device 200 can include sensor circuit240, 242, 244 (e.g., a standard resistor chain and signal filter)disposed on PCB 202 and configured to measure voltage and/or currentacross the feed circuit 168 of backup PV power generation system 160. Insome embodiments, sensor circuit 240, 242, 244 can include any type ofcircuitry component (e.g., a voltmeter, resistor chain, signal filter, apotential transformer, and/or a current transformer), to measure voltageand/or current across the feed circuit 168 of backup PV power generationsystem 160. As shown in FIG. 3 , sensor circuit 240, 242, 244 can beelectrically coupled to first phase line L1, second phase line L2,neutral line, and/or ground line of the feed circuit 168 from backup PVpower generation system 160. In some embodiments, sensor circuit 240,242, 244 can be connected only to first phase line L1, second phase lineL2, and/or neutral line, not the ground line. In some embodiments,sensor circuit 240-244 is configured to measure voltage and/or currentacross the feed circuit 168 of the backup PV power generation system 160in reference to the neutral wire of the feed circuit 168(line-to-neutral).

In some embodiments, PV disconnect device 200 can include a connectorport 250 electrically coupled to energy control system 110, to allow,for example, opto-coupled signaling between energy control system 110and PV disconnect device 200. In some embodiments, connector port 250 isconfigured to allow force open, force closed, and autonomous operationsignaling between the energy control system 110 and PV disconnect device200. In some embodiments, connector port 250 can include any type ofcircuit to establish an electrical connection with energy control system110. In some embodiments, connector port 250 is configured to allow“relay state sense feedback” between energy control system 110 and PVdisconnect device 200. In some embodiments, connector port 250 candefine the isolation boundary between the feed circuit 168 from backupPV power generation system 160 and energy control system 110.

In some embodiments, PV disconnect device 200 can include a relaycontroller 260 (e.g., a microcontroller) disposed on PCB 202 andoperatively connected to first relay 210, second relay 220, relay driver230, sensor circuit 240-244, and/or connector port 250. In someembodiments, relay controller 260 can be configured to receive thevoltage measurements from sensor circuit 240-244. In some embodiments,relay controller 260 can be configured to actuate relay driver 230 toopen and/or close first relay 210 and/or second relay 220. In someembodiments, relay controller 260 can be configured to transmit throughrelay driver 230 a first drive signal to the first relay 210 and asecond drive signal to second relay 220 to actuate electricaldisconnection between backup PV power generation system 160 and energycontrol system 110. In some embodiments, the relay controller 260 cantransmit the first and second drive signals simultaneously. In someembodiments, relay controller 260 can include an analog-to-digitalconverter to convert analog signals received from sensor circuit 240-244to digital signals. In some embodiments, relay controller 260 caninclude a processor for processing input signals and sending commandsvia output signals.

In some embodiments, relay controller 260 can include memory forstoring, for example, information about storage system 150, backup PVpower generation system 160, non-backup PV power generation system 190,and/or energy control system 110. In some embodiments, relay controller260 can include firmware stored in the memory of relay controller 260for controlling operation of PV disconnect device 200. In someembodiments, the firmware of relay controller 260 can includealgorithms, including any of the algorithms described herein, thatenable the relay controller 260 to process voltage measurements fromsensor circuit 240-244. In some embodiments, execution of the storedalgorithms can allow relay controller 260 to detect peak voltage andcompare data (e.g., voltage measurements of the feed circuit 168, poweroutput of backup PV power generation system 160) to predeterminedthresholds. In some embodiments, execution of the firmware can allow therelay controller 260 to process power output data of backup PV powergeneration system 160 and actuate relay driver 230 based on theprocessed voltage measurements.

In some embodiments, PV disconnect device 200 can include a powerconverter 270 electrically coupled to feed circuit 168 from backup PVpower generation system 160. In some embodiments, power converter 270can be configured to reduce the voltage inputted from the feed circuit168 of the backup PV power generation system 160 to a minimal operatingvoltage. In some embodiments, power converter 270 can convert ACinputted from the feed circuit 168 of the backup PV power generationsystem 160 to DC that is used to power components of PV disconnectdevice 200, such as relay controller 260. In some embodiments, powerconverter 270 can include any type of circuitry, such as input fuses,resistors, semiconductors, inductance coils, and transformers, toconvert between AC/DC and reduce input voltage.

FIG. 4 shows a configuration of a PV disconnect device 200 according tosome embodiments. PV disconnect device 200 as shown in FIG. 4 caninclude the same or similar features as the embodiments of PV disconnectdevice described herein (e.g., PV disconnect device 200 shown in FIG. 3), including PCB 202, first relay 210, second relay 220, relay driver230, sensor circuit 240-244, connector port 250, relay controller 260,and/or power converter 270. In some embodiments, as shown in FIG. 4 forexample, PV disconnect device 200 can include an interface 280 that isconfigured to communicate with other components of electrical system100, such as controller 122 and PV monitoring system 130 of energycontrol system 110, PV inverter 162 of backup PV power generation system160, and/or storage converter 154 of storage system 150. In someembodiments, interface 280 can communicate according to RS-485 (e.g.,modbus) or CAN standard or any other similar communication standard.

In some embodiments, PV disconnect device 200 can be integrated withother components of electrical system 100, including any component inenergy control system 110, energy storage system 150, and backup PVpower generation system 160. In some embodiments, as shown in FIG. 2 forexample, PV disconnect device 200 can be integrated with controller 1500of energy control system 110.

In some embodiments, as shown in FIG. 5 for example, PV disconnectdevice 200 can include only a relay component, such as first relay 210,second relay 220, and relay driver 230, without having sensor circuit, acontroller, a connector port, and/or a power converter. In someembodiments, such as the configuration shown in FIG. 5 , PV disconnectdevice 200 can be controlled by controller 122, which receives voltagemeasurements of the feed circuit 168 from backup PV power generationsystem 160 and actuates relay driver 230 of PV disconnect device 200based on processing of the voltage and/or current measurements. In someembodiments, the sensor circuit 240-244, the relay controller 260, theconnector port 250, and/or the power converter 270, as described hereinwith respect to the embodiments shown in FIGS. 3 and 4 , for example,can be located on the PCB of controller 122 or PV monitoring system 130.

FIGS. 6-9 show embodiments of integrating energy control system 110 andone or more PV disconnect devices (e.g., PV disconnect device 200, afirst PV disconnect device 200A, and a second PV disconnect device 200B)with different electrical systems having various types of loads, PVpower generation configurations, and energy storage capacities. Similarto the embodiment shown in FIG. 1 , each of the electrical systems shownin FIGS. 6-9 can include energy control system 110, backup PVinterconnection 111, storage interconnection 112, backup loadinterconnection 113, non-backup interconnection 115, gridinterconnection 116 with non-backup power bus 180, microgridinterconnection device 120, housing 121, controller 122, energy storagesystem 150, backup PV power generation system 160 having one or morepower generation arrays 164, and a plurality of backup loads 172. Insome embodiments, each of the electrical systems shown in FIGS. 6-9 caninclude any other feature from the embodiment shown in FIG. 1 .

FIG. 6 shows an electrical system 300, according to an embodiment, inwhich PV disconnect device 200 is disposed within housing 121 of energycontrol system 110. As shown in FIG. 6 , in some embodiments, energycontrol system 110 can include microgrid interconnection device 120 andcontroller 122 disposed in housing 121. In some embodiments, energycontrol system 110 can include backup power bus 140 electrically coupledto a backup side (e.g., a load side) of microgrid interconnection device120, for example, via a load-side lug. In some embodiments, backup powerbus 140 can be electrically coupled to backup PV power generation system160 via backup PV interconnection 111, energy storage system 150 viastorage interconnection 112, and the plurality of backup loads 172 viabackup load interconnection 113. In some embodiments, energy controlsystem 110 can include non-backup power bus 180 electrically coupled toa non-backup side (e.g., a line side) of micro-grid interconnectiondevice 120. In some embodiments non-backup power bus 180 can beelectrically coupled to over-current-protection device 182 (e.g., mainservice panel with a main circuit breaker, such as a 200 A circuitbreaker) that is electrically coupled to the utility grid. Due to wiringprotection in electrical regulations, for example, PV disconnect device200 cannot be electrically located between PV power generation arrays164 and AC breakers 118, which, for example, are located along backup PVinterconnection 111. Accordingly, in some embodiments, PV disconnectdevice 200 can be electrically coupled to backup power bus 140 anddisposed inside housing 121 so that AC breaker 118 protects PVdisconnect device 200 from power surges carrying high amperage currents(e.g., 20 amps or greater).

While only one PV disconnect device 200 is shown in FIG. 6 , electricalsystem 300 can include multiple PV disconnect devices disposed atdifferent locations in electrical system 300 such that each PVdisconnect device 200 is configured to decouple a respective PV powergeneration array 164 from energy control system 110. In someembodiments, each PV disconnect device 200 can be controlledindependently (e.g., by controller 122 and/or PV monitoring system 130)to selectively decouple a respective PV power generation array 164 fromenergy control system 110. By selectively disconnecting any one of PVpower generation arrays 164 through independent control of multiple PVdisconnect devices 200, energy control system 110 can reduce poweroutput from part of backup PV power generation system 160 whilemaintaining power output from the remainder of backup PV powergeneration system 160. In some embodiments, all PV disconnect devices200 can be controlled collectively (e.g., at the same time) such thatall PV power generation arrays 164 can be electrically decoupled fromenergy control system 110 (e.g., simultaneously). By collectivelycontrolling all PV disconnect devices 200 simultaneously, energy controlsystem 110 can reduce the entire power output from backup PV powergeneration system 160 in response to one or more conditions, such as,for example, when batteries 158 are fully charged or when rapid powershutdown is demanded by a user.

FIG. 7 shows an electrical system 400, according to an embodiment, inwhich PV disconnect device 200 is disposed outside of housing 121 ofenergy control system 110. For example, electrical system 400 can beretrofitted with components (e.g., a subpanel) of backup PV powergeneration system 160 that were installed before implementation ofenergy control system 110. As shown in FIG. 7 , in some embodiments,backup PV power generation system 160 can include a subpanel 166electrically coupled to a plurality of PV power generation arrays 164and electrically coupled to energy control system 110. In someembodiments, PV disconnect device 200 can be disposed outside of housing121. In some embodiments, as shown by pathway A, PV disconnect device200 can be electrically coupled (e.g., directly wired) to PVinterconnection 111 if subpanel 166 does not have an existing primaryovercurrent protection device. In some embodiments, as shown by pathwayB, PV disconnect device 200 can be electrically coupled (e.g., directlywired) to backup power bus 140 if subpanel 166 has an existing primaryovercurrent protection device.

While only one PV disconnect device 200 is shown in FIG. 7 , electricalsystem 400 can include multiple PV disconnect devices disposed atdifferent locations in electrical system 400 such that each PVdisconnect device 200 is configured to decouple a respective PV powergeneration array 164 from energy control system 110. In someembodiments, each PV disconnect device 200 can be controlledindependently (e.g., by controller 122 and/or PV monitoring system 130)to selectively decouple a respective PV power generation array 164 fromenergy control system 110. By selectively disconnecting any one of PVpower generation arrays 164 through independent control of multiple PVdisconnect devices 200, energy control system 110 can reduce poweroutput from part of backup PV power generation system 160 whilemaintaining power output from the remainder of backup PV powergeneration system 160. In some embodiments, all PV disconnect devices200 can be controlled collectively (e.g., at the same time) such thatall PV power generation arrays 164 can be electrically decoupled fromenergy control system 110 (e.g., simultaneously). By collectivelycontrolling all PV disconnect devices 200 simultaneously, energy controlsystem 110 can reduce the entire power output from backup PV powergeneration system 160 in response to one or more conditions, such as,for example, when batteries 158 are fully charged or when rapid powershutdown is demanded by a user.

FIG. 8 shows an electrical system 500, according to an embodiment,including a first PV disconnect device 200A disposed upstream of thebackup side of microgrid interconnection device 120 (e.g., withinhousing 121) and a second PV disconnect device 200B disposed upstream ofthe non-backup side of microgrid interconnection device 120 (e.g.,outside of housing 121). In some embodiments, first and second PVdisconnect devices 200A-B can include any component of the otherembodiments of PV disconnect devices described herein. In someembodiments, first PV disconnect device 200A can be electrically coupledto backup power bus 140 and disposed inside housing 121 (e.g., alongpathway A), similar to the location of PV disconnect device 200 shown inFIG. 6 . As shown in FIG. 8 , electrical system 500 can includenon-backup PV power generation system 190 having one or more PV powergeneration arrays 194 electrically coupled to a subpanel 196. In someembodiments, second PV disconnect device 200B can be disposed downstreamof at least one non-backup power generation array 194 and upstream ofthe non-backup side of microgrid interconnection device 120, wheresecond PV disconnect device 200B is disposed outside of housing 121(e.g., along pathway B). Because AC beakers need to be electricallyupstream of second PV disconnect device 200B, non-backup PV powergeneration system 190 includes subpanel 196 (e.g., with AC breakers 197)disposed upstream of second PV disconnect device 200B. In someembodiments, second PV disconnect device 200B is electrically coupled tonon-backup PV interconnection 115. In some embodiments, second PVdisconnect device 200B can include its own housing (e.g., non-metallichousing).

The arrangement of second PV disconnect device 200B allows theelectrical system to increase the power generation capacity of a PVpower generation system while still affording protection to backup powerbus 140 such that backup power bus 140 remains compliant with NationalElectrical Code (NEC) 2020 PCS controls (e.g., ratings for electricpanels). For example, if a user would like to have a total of 100 kW ofpower output by a PV power generation system using a 100 A rated backuppower bus 140, a majority of the total 100 kW power output (e.g., 80 kW)can be provided by non-backup PV power generation system 190 backup PVpower generation system 160, whereas a smaller fraction (e.g., 20 kW) ofthe total 100 kW power output can be provided by the backup PV powergeneration system 160. The second PV disconnect device 200B allowscontroller 122 to eliminate power supply from non-backup PV powergeneration system 190 to meet national standards like NEC 2020 or Rapidshut down functionality.

While only two PV disconnect devices 200A, 200B are shown in FIG. 8 ,electrical system 500 can include multiple PV disconnect devicesdisposed at different locations in electrical system 500 such that eachPV disconnect device 200 is configured to decouple a respective PV powergeneration array 164, 194 from energy control system 110. In someembodiments, each PV disconnect device 200A, 200B can be controlledindependently (e.g., by controller 122 and/or PV monitoring system 130)to selectively decouple a respective PV power generation array 164, 194from energy control system 110. By selectively disconnecting any one ofPV power generation arrays 164, 194 through independent control ofmultiple PV disconnect devices 200A, 200B, energy control system 110 canreduce power output from part of backup PV power generation system 160and/or non-backup PV power generation system 190 while maintaining poweroutput from the remainder of backup PV power generation system 160and/or non-backup PV power generation system 190. In some embodiments,all PV disconnect devices 200 can be controlled collectively (e.g., atthe same time) such that all PV power generation arrays 164, 194 can beelectrically decoupled from energy control system 110 (e.g.,simultaneously). By collectively controlling all PV disconnect devices200 simultaneously, energy control system 110 can reduce the entirepower output from backup PV power generation system 160 and/ornon-backup PV power generation system 190 in response to one or moreconditions, such as, for example, when batteries 158 are fully chargedor when rapid power shutdown is demanded by a user.

FIG. 9 shows an electrical system 600, according to an embodiment,including first PV disconnect device 200A and second PV disconnectdevice 200B both disposed upstream of the backup side of microgridinterconnection device. As shown in FIG. 9 , first PV disconnect device200A can be electrically coupled to backup power bus 140 and disposedinside housing 121 (e.g., along pathway A), similar to the location ofPV disconnect device 200 shown in FIG. 6 . In some embodiments,electrical system 600 can include backup PV power generation system 160having a high power output capacity (e.g., 30 kW or greater) such thatbackup PV power generation system 160 includes additional powergeneration arrays 164 and one or more subpanels 166 electrically coupledto additional power generation arrays 164. In some embodiments, secondPV disconnect device 200B can be disposed downstream of additional powergeneration arrays 194 and subpanel 196, where second PV disconnectdevice 200B is disposed outside of housing 121 (e.g., along pathway B).In some embodiments, second PV disconnect device 200B can include itsown housing. In some embodiments, subpanel 196 includes one or more ACbreakers 197 to protect second PV disconnect device 200B from excesscurrent. The arrangement of first and second PV disconnect devices200A-B shown in FIG. 9 allows a user to place more backup PV poweroutput while still affording backup power bus 140 to remain compliantwith NEC 2020 PCS controls (e.g., ratings for electric panels).

While only two PV disconnect devices 200A, 200B are shown in FIG. 9 ,electrical system 600 can include multiple PV disconnect devicesdisposed at different locations in electrical system 600 such that eachPV disconnect device 200 is configured to decouple a respective PV powergeneration array 164, 194 from energy control system 110. In someembodiments, each PV disconnect device 200A, 200B can be controlledindependently (e.g., by controller 122 and/or PV monitoring system 130)to selectively decouple a respective PV power generation array 164, 194from energy control system 110. By selectively disconnecting any one ofPV power generation arrays 164, 194 through independent control ofmultiple PV disconnect devices 200A, 200B, energy control system 110 canreduce power output from part of backup PV power generation system 160and/or non-backup PV power generation system 190 while maintaining poweroutput from the remainder of backup PV power generation system 160and/or non-backup PV power generation system 190. In some embodiments,all PV disconnect devices 200 can be controlled collectively (e.g., atthe same time) such that all PV power generation arrays 164, 194 can beelectrically decoupled from energy control system 110 (e.g.,simultaneously). By collectively controlling all PV disconnect devices200 simultaneously, energy control system 110 can reduce the entirepower output from backup PV power generation system 160 and/ornon-backup PV power generation system 190 in response to one or moreconditions, such as, for example, when batteries 158 are fully chargedor when rapid power shutdown is demanded by a user.

FIG. 10 shows an example block diagram illustrating a method 1000,according to an embodiment, of controlling a PV disconnect device (e.g.,PV disconnect device 200, a first PV disconnect device 200A, and/or asecond PV disconnect device 200B) by a controller, such as, for example,controller 122 and/or PV monitoring system 130 of microgridinterconnection device 120. One or more aspects of method 1000 can beimplemented using hardware, software modules, firmware, tangiblecomputer readable media having instructions stored thereon, or acombination thereof and can be implemented in one or more computersystems or other processing systems.

In some embodiments, method 1000 can include a step 1010 of monitoringelectronic data of an electrical system (e.g., any of the electricalsystems described herein, such as electrical system 100). In someembodiments, step 1010 can include receiving (e.g., by controller 122)electronic data related to backup PV power generation system 160, energystorage system 150, utility grid 184, the plurality of backup loads 172,and/or non-backup loads 174. For example, in some embodiments,electronic data related to backup PV power generation system 160 caninclude a detected power output of backup PV power generation system160. In some embodiments, electronic data related to backup PV powergeneration system 160 can include a frequency of the power supplied bybackup PV power generation system 160. In some embodiments, electronicdata related to energy storage system 150 can include an availablestorage capacity. In some embodiments, electronic data related to theplurality of backup loads 172 can include a current backup load demand.In some embodiments, electronic data related to the plurality ofnon-backup loads 174 can include a current non-backup load demand. Insome embodiments, electronic data related to utility grid 184 caninclude an operating status of utility grid 184 electrically coupled tomicrogrid interconnection device 120 (e.g., grid-tied or power outage).

In some embodiments, method 1000 can include a step 1020 of determiningwhether the monitored electronic data indicates a power deviation event.In some embodiments, a power deviation event can be when power suppliedto backup power bus 140 exceeds a threshold (e.g., 120% of bus barrating) that would overwhelm electrical system 100.

In some embodiments, step 1020 can include comparing the measured poweroutput of backup PV power generation system 160 to the available storagecapacity of energy storage system 150. In some embodiments, a powerdeviation event occurs when the power output of backup PV powergeneration system 160 is greater than the available storage capacity ofenergy storage system 150. For example, backup PV power generationsystem 160 can supply up to a 15 kW power output, and energy storagesystem 150 has a total storage capacity of 6 kW. During the middle ofthe morning (e.g., 11:00 AM), when the power output of backup PV powergeneration system 160 is climbing (e.g., measured power output 7 kW),controller 122 can detect that the 7 kW power output by backup PV powergeneration system 160 is greater than the storage capacity of energystorage system 150, and therefore, determine that a power deviationevent has occurred.

In some embodiments, step 1020 can include determining whether the loaddemand by backup loads 172 and/or non-backup loads 174 decreases below athreshold value within a set time period (e.g., an excessive load drop).In some embodiments, the threshold value for a load demand drop canrange from about 5 kW to about 10 kW, such as, for example, about 5 kWto about 7.5 kW. In some embodiments, the time period can range fromabout 1 second to about 1 hour, such as for example, about 1 minute toabout 5 minutes.

In some embodiments, step 1020 can include detecting when the operatingstatus of utility grid 184 indicates a power outage. When there is apower outage, microgrid interconnection device 120 switches to thebackup mode in which microgrid interconnection device 120 electricallydisconnects non-backup power bus 180 from backup power bus 140. Whenmicrogrid interconnection device 120 is set in backup mode, any poweroutput by backup PV power generation system 160 that is in excess of theload demand cannot be synced back to the utility grid, therebypotentially resulting in a large power differential that can overwhelmenergy control system 110. Accordingly, in some embodiments, controller122 can determine that a power deviation event has occurred whenimmediately detecting a power outage of the utility grid.

In some embodiments, step 1020 can include detecting the number of timesthat a measured frequency of the power supplied by backup PV powergeneration system 160 exceeds a setpoint frequency, such as, for examplea 60 Hz setpoint frequency that is compliant with the utility grid. Thefrequency of backup PV power generation system 160 increases when therate of power supply exceeds the charging rate of storage of energystorage system 150 and/or backup load demand. In some embodiments,electrical system 100 can operate according to a frequency-watt PVcurtailment scheme, in which converters curtail power output of backupPV power generation system 160 when the measured frequency rises above asetpoint frequency (e.g., 60 Hz). However, frequency-watt control can betoo slow to adjust PV power output, thereby resulting in the frequencyof PV power supply rising above the setpoint frequency multiple times ina day. For example, even if the power output of backup PV powergeneration system is relatively small (e.g., about 3 kW to about 5 kW),the frequency of power supply can still rise above the set pointfrequency if there is current low backup load demand (e.g., about 200 Wto about 300 W) and the energy storage system 150 is at a high state ofcharge (e.g., about 97% to about 99%). Accordingly, in some embodiments,controller 122 can determine that a power deviation event has occurredwhen the monitored frequency of the power supplied by the backup PVpower generation system 160 rises above a setpoint frequency (e.g., 60Hz) more than a maximum number of times within a set time period. Insome embodiments, the maximum number of times can range from 1 time to10 times, such as, for example, 3 to 4 times. In some embodiments, theset time period can range from 1 minute to 48 hours, such as forexample, 3 hours to 24 hours.

In some embodiments, method 1000 can include a step 1030 of keeping PVdisconnect device 200 closed when not detecting a power deviation eventbased on the monitored electronic data. For example, if the availablestorage capacity or load demand matches or exceeds the measured poweroutput, controller 122 cannot actuate PV disconnect device 200 so thatpower supply by backup PV power generation system 160 can still beutilized to meet load demand or charge the energy storage system 150.

In some embodiments, method 1000 can include a step 1040 of opening PVdisconnect device 200 when detecting a power deviation event based onthe monitored electronic data. For example, once the monitored poweroutput of the backup PV power generation system 160 exceeds theavailable storage capacity of energy storage system 150, controller 122can actuate PV disconnect device 200 to be open within a predeterminedresponse time (e.g., about 10 milliseconds to about 40 milliseconds) toprevent any potential damage to the electrical system. In someembodiments, controller 122 can then keep PV disconnect device 200 openfor a predetermined time period (e.g., about 3 hours to about 5 hours)to avoid rising PV power output during the daytime or allow sufficientamount of time for the energy storage system 150 to increase its storagecapacity. In another example, when there is an excessive load drop or apower outage, controller 122 can actuate PV disconnect device 200 to beopen within a predetermined response time (e.g., about 10 millisecondsto about 40 milliseconds) to prevent any potential damage or disruptionto the electrical system. In another example, when the when themonitored frequency of the power supplied by backup PV power generationsystem 160 rises above the setpoint frequency more than a maximum numberof times (e.g., two, three, or four times) within a set time period(e.g., four hours, 12 hours, 24 hours), controller 122 can actuate PVdisconnect device 200 to be open within a predetermined response time(e.g., about 10 milliseconds to about 40 milliseconds) to preventpotential damage to the electrical system.

FIG. 11 illustrates an example computer system 1100 that can beimplemented in controller 122, PV monitoring system 130, and/or PVdisconnect device 200. In some embodiments, computer system 1100 caninclude a processor device 1104. Processor device 1104 can be a specialpurpose or a general purpose processor device. As will be appreciated bypersons skilled in the relevant art, processor device 1104 can also be asingle processor in a multi-core/multiprocessor system, such systemoperating alone, or in a cluster of computing devices operating in acluster or server farm. Processor device 1104 can be connected to acommunication infrastructure 1106, for example, a bus, message queue,network, or multi-core message-passing scheme.

In some embodiments, computer system 1100 can include a main memory1108, for example, read only memory (ROM) and/or random access memory(RAM), and can also include a secondary memory 1110. Secondary memory1110 can include, for example, a hard disk drive 1112, and/or removablestorage drive 1114. Removable storage drive 1114 can include a floppydisk drive, a magnetic tape drive, an optical disk drive, a flashmemory, a Universal Serial Bus (USB) drive, or the like. The removablestorage drive 1114 reads from and/or writes to a removable storage unit1118 in a well-known manner. Removable storage unit 1118 can include afloppy disk, magnetic tape, optical disk, etc. which is read by andwritten to by removable storage drive 1114. As will be appreciated bypersons skilled in the relevant art, removable storage unit 1118includes a computer usable storage medium having stored therein computersoftware instructions and/or data.

In some embodiments, computer system 1100 can include a displayinterface 1102 (which can include input and output devices such askeyboards, mice, etc.) that presents graphics, text, and other data fromcommunication infrastructure 1106 (or from a frame buffer not shown) fordisplay, for example, on display unit 1130.

In some embodiments, secondary memory 1110 can include other similarmeans for allowing computer programs or other instructions to be loadedinto computer system 1100. Such means can include, for example, aremovable storage unit 1122 and an interface 1120. Examples of suchmeans can include a program cartridge and cartridge interface (such asthat found in video game devices), a removable memory chip (such as anEPROM, or PROM) and associated socket, and other removable storage units1122 and interfaces 1120 which allow software and data to be transferredfrom the removable storage unit 1122 to computer system 1100.

Computer system 1100 can also include a communication interface 1124.Communication interface 1124 allows software and data to be transferredover a network between computer system 1100 and external devices.Communication interface 1124 can include a modem, a network interface(such as an Ethernet card), a communication port, a PCMCIA slot andcard, or the like. Software and data transferred via communicationinterface 1124 can be in the form of signals, which can be electronic,electromagnetic, optical, or other signals capable of being received bycommunication interface 1124. These signals can be provided tocommunication interface 1124 via a communication path 1126.Communication path 1126 carries signals and can be implemented usingwire or cable, fiber optics, a phone line, a cellular phone link, an RFlink or other communication channels.

In the context of the present disclosure, the terms “computer programmedium” and “computer usable medium” are used to generally refer tomedia such as removable storage unit 1118, removable storage unit 1122,and a hard disk installed in hard disk drive 1112. Computer programmedium and computer usable medium can also refer to memories, such asmain memory 1108 and secondary memory 1110, which can be memorysemiconductors (e.g., DRAMs, etc.).

Computer programs (also called computer control logic) are stored inmain memory 1108 and/or secondary memory 1110. Computer programs canalso be received via communication interface 1124. Such computerprograms, when executed, enable computer system 1100 to implement theembodiments as discussed herein. In particular, the computer programs,when executed, enable processor device 1104 to implement the processesof the embodiments discussed here. Accordingly, such computer programsrepresent controllers of the computer system 1100. Where the embodimentsare implemented using software, the software can be stored in a computerprogram product and loaded into computer system 1100 using removablestorage drive 1114, interface 1120, and hard disk drive 1112, orcommunication interface 1124.

Embodiments of the present disclosure also can be directed to computerprogram products comprising software stored on any computer useablemedium. Such software, when executed in one or more data processingdevice, causes a data processing device(s) to operate as describedherein. Embodiments of the present disclosure can employ any computeruseable or readable medium. Examples of computer useable mediumsinclude, but are not limited to, primary storage devices (e.g., any typeof random access memory) and secondary storage devices (e.g., harddrives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storagedevices, and optical storage devices, MEMS, Nano technological storagedevice, etc.).

In some embodiments, the operation of PV disconnect device 200 can becontrolled according to an adaptive feedforward control mode (e.g., inthe form computer readable instructions) based on one or more inputs,such as, for example, an instantaneous PV power output, a current timeof day, and/or a predicted PV power output. In some embodiments, thefeedforward control mode can configure PV disconnect device 200 todisconnect backup PV power generation system 160 within a predeterminedtime range, such as, for example, from approximately 10 milliseconds toapproximately 20 milliseconds, to expedite the response time of PVdisconnect device 200. By expediting the response time of PV disconnectdevice 200, the adaptive feedforward control mode configures PVdisconnect device 200 to disconnect backup PV power generation system160 before a microgrid is formed when microgrid interconnection device120 switches from on-grid mode to backup mode. For example, in someembodiments, when microgrid interconnection device 120 switches fromon-grid mode to backup mode, a microgrid is formed between the pluralityof backup loads 172 and energy storage system 150 in a time range fromapproximately 40 milliseconds to approximately 60 milliseconds, whereasPV disconnect device 200 disconnects backup PV power generation system160 from energy control system 110 in a time range less than 40milliseconds, such as for example, less than approximately 30milliseconds (e.g., from approximately 10 milliseconds to approximately20 milliseconds).

In some embodiments, the adaptive feedforward control mode can configurePV disconnect device 200 to be opened or closed for a predetermined timeperiod. In some embodiments, the predetermined time period can be mappedin a lookup table according to one or more inputs (e.g., instantaneousPV power output and/or current time of day). For example, as shown inFIG. 12 , a lookup table 1150 can reside in the form of computerreadable instructions stored in the memory (e.g., ROM of main memory1108) of computer system 1100 implemented in controller 122, PVmonitoring system 130, and/or PV disconnect device 200 for controllingthe operation of PV disconnect device 200. In some embodiments, as shownin FIG. 12 , for example, lookup table 1150 can include a first field(e.g., column and/or row) 1152 listing values of PV power output, asecond field (e.g., column and/or row) 1154 listing times of the day, athird field (e.g., column and/or row) 1156 listing predetermined timeperiods for keeping PV disconnect device 200 open or closed, and/or afourth field (e.g., column and/or row) 1158 listing an estimated PVpower output at the end of the predetermined time period. In someembodiments, PV disconnect device 200 can automatically be set in anopen state or a closed state according to the predetermined time periodlisted in third field 1156 of lookup table 1150. In some embodiments,the estimated PV power output listed in fourth field 1158 can be updatedaccording to a control algorithm that accounts for historical PV poweroutput and forecast PV power output. Accordingly, the predetermined timeperiods can be adjusted over an extended period of time to account forfeedback of electrical system 100.

In some embodiments, the predetermined time periods listed in thirdfield 1156 of lookup table 1150 can be based on PV power output profilegraph 1300 shown in FIG. 13 . In some embodiments, as shown in FIG. 13 ,PV power output profile graph 1300 can indicate a first time period 1302when predicted backup PV power output is greater than a predicted loaddemand and/or available storage capacity of energy storage system 150,such as, for example, during the hours of maximum of solar exposure(e.g., from 8:00 am to 3:00 pm). In some embodiments, PV power outputprofile graph 1300 can indicate a second time period 1304 when thepredicted backup PV power output is less than the predicted load demandby the plurality of backup loads 172 and/or available storage capacityof energy storage system 150, such as, for example, during the hours oflimited solar exposure (e.g., 3:00 pm to 8:00 am). In some embodiments,the PV power output graph can be updated over time based on historicaldata. In some embodiments, the predetermined time periods listed inthird field 1156 can range from approximately 5 minutes to approximately24 hours, such as, for example, from approximately 1 hour toapproximately 8 hours. For example, the predetermined time periods foropening PV disconnect device 200 during the morning of first time period1302 can be greater than the predetermined time periods for opening PVdisconnect device 200 during the afternoon of first time period 1302 toallow backup PV power generation system 160 to be disconnected whengenerating maximum power, ultimately preventing backup PV powergeneration system 160 from overloading the load demand of backup loads172 and/or available storage capacity of energy storage system 150.

In operation under the feedforward control mode, a processor (e.g.,processor device 1104) of controller 122, PV monitoring system 130,and/or PV disconnect device 200 can detect the instantaneous PV poweroutput of backup PV power generation system 160 and/or the current timeof day. In some embodiments, processor device 1104 can be configured toreceive data indicating the instantaneous PV power output according to apredetermined sampling rate, such as for example, a sampling rateranging from approximately 5 milliseconds to approximately 1 second,such as a 100 millisecond sampling rate. In some embodiments, processordevice 1104 can determine the address (e.g., corresponding row and/orcolumn) of first field 1152 in lookup table 1150 that corresponds to thedetected instantaneous PV power output. In some embodiments, processordevice 1104 can determine the address (e.g., corresponding row and/orcolumn) of second field 1154 in lookup table 1150 that corresponds tothe current time of the day. In some embodiments, processor device 1104can determine the address (e.g., corresponding row and/or column) ofthird field 1156 in lookup table 1150 based on the determined address(e.g., corresponding row and/or column) of first field 1152 and/or thedetermined address (e.g., corresponding row and/or column) of secondfield 1154. In some embodiments processor device 1104 can keep PVdisconnect device 200 in the open state or closed state according to thepredetermined time period set forth in the determined address (e.g.,corresponding row and/or column) of third field 1156 of lookup table1150.

In some embodiments, the operation of PV disconnect device 200 can becontrolled according to a dynamic control mode (e.g., in the formcomputer readable instructions). In some embodiments, the dynamiccontrol mode can configure PV disconnect device 200 to open or closebased on a control algorithm that accounts for one or more operatingconditions, such as, for example, voltage, current, and/or frequency ofAC across the feed circuit 168 of backup PV power generation system 160.In some embodiments, dynamic control mode configures PV disconnectdevice 200 to open or close according, for example, to method 1000 shownin FIG. 10 .

In some embodiments, processor device 1104 can be configured todetermine whether to operate PV disconnect device 200 in the feedforwardcontrol mode or in the dynamic control mode based on one or more inputs.For example, processor device 1104 can determine whether to operate PVdisconnect device 200 is in the feedforward control mode or the dynamicmode based on the detected instantaneous PV power output of backup PVpower generation system 160. In some embodiments, when detecting a gridoutage and/or when detecting that microgrid interconnection device 120has switched to backup mode, processor device 1104 can be configured tooperate in the feedforward control mode when the instantaneous PV poweroutput exceeds a first PV output threshold and in the dynamic controlmode when the instantaneous PV power output falls below the first PVoutput threshold. In some embodiments, the first PV output threshold canrange from approximately 7 kW to approximately 10 kW, such as, forexample 7.5 kW. The first PV output threshold can be determined based onthe power rating of backup PV power generation system 160, storagecapacity of energy storage system 150, and/or load demand of theplurality of backup loads 172. In some embodiments, when microgridinterconnection device 120 is operating in on-grid mode, processordevice 1104 can be configured to operate in the feedforward control modewhen the instantaneous PV power output exceeds a second PV outputthreshold and in the dynamic control mode when the instantaneous PVpower output falls below the second PV output threshold. In someembodiments, the second PV output threshold can range from approximately6 kW to approximately 10 kW, such as, for example 7 kW.

FIG. 14 shows an example block diagram illustrating a method 1400,according to an embodiment, of controlling a PV disconnect device (e.g.,PV disconnect device 200, a first PV disconnect device 200A, and/or asecond PV disconnect device 200B) by a controller, such as, for example,controller 122, PV monitoring system 130, and/or relay controller 260.One or more aspects of method 1400 can be implemented using hardware,software modules, firmware, tangible computer readable media havinginstructions stored thereon, or a combination thereof and can beimplemented in one or more computer systems or other processing systems(e.g., computer system 1100).

In some embodiments, method 1400 can include a step 1410 of receivingelectronic data indicating an instantaneous PV power output of backup PVpower generation system 160. In some embodiments, step 1410 canincluding using PV monitoring system 130 to receive PV power outputmeasurements at a sampling rate between approximately 10 millisecondsand approximately 1 second, such as, for example, a sampling rate of 100milliseconds.

In some embodiments, method 1400 can include a step 1420 of determiningwhether the instantaneous PV power output of backup PV power generationsystem 160 exceeds a PV output threshold. In some embodiments, the PVoutput threshold in step 1420 can include a first PV output thresholdwhen detecting a grid outage and/or when detecting that microgridinterconnection device 120 has switched to backup mode. In someembodiments, the PV output threshold in step 1420 can include a secondPV output threshold when microgrid interconnection device 120 isoperating in on-grid mode. In some embodiments, the first PV outputthreshold can be less than or greater than the second PV outputthreshold. In some embodiments, the first PV output threshold can rangefrom approximately 7 kW to approximately 10 kW, such as, for example 7.5kW. In some embodiments, the second PV output threshold can range fromapproximately 6 kW to approximately 10 kW, such as, for example 7 kW.

In some embodiments, when step 1420 indicates that the instantaneous PVpower output is less than the PV output threshold, method 1400 caninclude a step 1430 of operating PV disconnect device in dynamic controlmode. In some embodiments, step 1430 can include receiving electronicdata related to backup PV power generation system 160, energy storagesystem 150, utility grid 184, the plurality of backup loads 172, and/ornon-backup loads 174. For example, in some embodiments, electronic datarelated to backup PV power generation system 160 can include a detectedpower output of backup PV power generation system 160. In someembodiments, electronic data related to backup PV power generationsystem 160 can include a frequency of the power supplied by backup PVpower generation system 160. In some embodiments, electronic datarelated to energy storage system 150 can include an available storagecapacity. In some embodiments, electronic data related to the pluralityof backup loads 172 can include a current backup load demand. In someembodiments, electronic data related to the plurality of non-backuploads 174 can include a current non-backup load demand. In someembodiments, electronic data related to utility grid 184 can include anoperating status of utility grid 184 electrically coupled to microgridinterconnection device 120 (e.g., grid-tied or power outage).

In some embodiments, method 1400 can include a step 1435 of determiningwhether to open or close PV disconnect device 200 based on a controlalgorithm. For example, in some embodiments, the control algorithm candetermine how long to open or close PV disconnect device 200 based onthe received electronic data related to backup PV power generationsystem 160, energy storage system 150, utility grid 184, the pluralityof backup loads 172, and/or non-backup loads 174. In some embodiments,the control algorithm includes determining whether the monitoredelectronic data indicates a power deviation event, such as thealgorithms used in step 1020 of method 1000. For example, a powerdeviation event can be when power supplied to backup power bus 140exceeds a threshold (e.g., 120% of bus bar rating) that would overloadelectrical system 100. In some embodiments, a power deviation eventoccurs when the power output of backup PV power generation system 160 isgreater than the available storage capacity of energy storage system150.

In some embodiments, when step 1420 indicates that the instantaneous PVpower output is greater than the PV output threshold, method 1400 caninclude a step 1440 of operating PV disconnect device in feedforwardcontrol mode. In some embodiments, step 1440 includes detecting theinstantaneous PV power output of backup PV power generation system 160and the current time of the day. In some embodiments, step 1440 caninclude reading lookup table 1150 stored in memory of processor device1104.

In some embodiments, method 1400 can include a step 1445 of determiningwhether to open or close PV disconnect device 200 based on lookup table1150. In some embodiments, step 1445 can include determining the address(e.g., corresponding row and/or column) of first field 1152 in lookuptable 1150 that corresponds to the detected instantaneous PV poweroutput. In some embodiments, step 1445 can include determining theaddress (e.g., corresponding row and/or column) of second field 1154 inlookup table 1150 that corresponds to the current time of the day. Insome embodiments, step 1445 can include determining the address (e.g.,corresponding row and/or column) of third field 1156 in lookup table1150 based on the determined address (e.g., corresponding row and/orcolumn) of first field 1152 and/or the determined address (e.g.,corresponding row and/or column) of second field 1154. In someembodiments, step 1445 can include keeping PV disconnect device 200 inthe open state or closed state according to the predetermined timeperiod set forth in the determined address (e.g., corresponding rowand/or column) of third field 1156 of lookup table 1150.

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections may set forth one or morebut not all exemplary embodiments of the present embodiments ascontemplated by the inventor(s), and thus, are not intended to limit thepresent embodiments and the appended claims in any way.

The present disclosure has been described above with the aid offunctional building blocks illustrating the implementation of specifiedfunctions and relationships thereof. The boundaries of these functionalbuilding blocks have been arbitrarily defined herein for the convenienceof the description. Alternate boundaries can be defined so long as thespecified functions and relationships thereof are appropriatelyperformed.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the embodiments that others can, byapplying knowledge within the skill of the art, readily modify and/oradapt for various applications such specific embodiments, without undueexperimentation, without departing from the general concept of thepresent disclosure. Therefore, such adaptations and modifications areintended to be within the meaning and range of equivalents of thedisclosed embodiments, based on the teaching and guidance presentedherein. It is to be understood that the phraseology or terminologyherein is for the purpose of description and not of limitation, suchthat the terminology or phraseology of the present specification is tobe interpreted by the skilled artisan in light of the teachings andguidance.

What is claimed is:
 1. An electrical system, comprising: an energycontrol system comprising a microgrid interconnection deviceelectrically coupled to a utility grid; a backup photovoltaic (PV) powergeneration system electrically coupled to the microgrid interconnectiondevice of the energy control system, the backup PV power generationsystem configured to generate and supply power, wherein the backup PVpower generation system comprises a PV panel and an inverterelectrically coupled to the PV panel; an energy storage systemelectrically coupled to the microgrid interconnection device of theenergy control system, the energy storage system having one or moreenergy storage units configured to store power supplied by the backup PVpower generation system; and a PV disconnect device electrically coupledto the backup PV power generation system and the energy control system,wherein the PV disconnect device is disposed electrically downstreamfrom the inverter of the backup PV power generation system andelectrically upstream from the microgrid interconnection device, and thePV disconnect device is configured to electrically disconnect the backupPV power generation system from the microgrid interconnection device ofthe energy control system, wherein the microgrid interconnection deviceis configured to electrically disconnect the utility grid from thebackup PV power generation system and the energy storage system within afirst response time range, and the PV disconnect device is configuredelectrically disconnect the backup PV power generation system from themicrogrid interconnection device within a second response time range,wherein the second response time range is less than the first responsetime range.
 2. The electrical system of claim 1, wherein the energycontrol system comprises a backup power bus electrically coupled to thebackup PV power generation system and the energy storage system, andwherein the PV disconnect device is disposed downstream of the backup PVpower generation system and upstream of the backup power bus.
 3. Theelectrical system of claim 1, wherein the energy control systemcomprises a housing and the microgrid interconnection device is disposedin the housing.
 4. The electrical system of claim 3, wherein the PVdisconnect device is disposed in the housing of the energy controlsystem and is in communication with a controller of the microgridinterconnection device.
 5. The electrical system of claim 1, wherein themicrogrid interconnection device is electrically coupled to at least onebackup load, and the electrical system further comprises: a controllerin communication with the microgrid interconnection device and the PVdisconnect device, the controller configured to monitor electronic dataof the electrical system, wherein the controller is configured to detecta power deviation event based on the monitored electronic data andactuate the PV disconnect device to disconnect the backup PV powergeneration system from the microgrid interconnection device when thepower deviation event is detected.
 6. The electrical system of claim 5,wherein the electronic data includes at least one of a power output ofthe backup PV power generation system, an available storage capacity ofthe energy storage system, and a current load demand by the at least onebackup load.
 7. The electrical system of claim 6, wherein the powerdeviation event includes when the monitored power output of the backupPV power generation system is greater than the available storagecapacity of the energy storage system.
 8. The electrical system of claim6, wherein the power deviation event includes when the load demand bythe at least one backup load decreases below a threshold value within aset time period.
 9. The electrical system of claim 5, wherein theelectronic data includes an operating status of the utility gridelectrically coupled to the microgrid interconnection device, and thepower deviation event includes when the operating status indicates apower outage of the utility grid.
 10. The electrical system of claim 5,wherein the electronic data includes a frequency of the power suppliedby the backup PV power generation system, and the power deviation eventincludes when the monitored frequency of the power supplied by thebackup PV power generation system rises above a setpoint frequency morethan a predetermined number of times within a predetermined time period.11. The electrical system of claim 5, wherein after disconnecting thebackup PV power generation system from the microgrid interconnectiondevice, the controller is configured to keep the PV disconnect device inan open state for a predetermined time period.
 12. The electrical systemof claim 11, wherein the predetermined time period is based on analgorithm or a lookup table.
 13. The electrical system of claim 1,wherein the PV disconnect device comprises at least one of anelectromechanical relay, a solid-state relay, and a controllablealternating current breaker electrically coupled to the backup PV powergeneration system.
 14. The electrical system of claim 1, wherein thefirst response time range is a range from approximately 40 millisecondsto approximately 60 milliseconds, and the second response time range isa range from approximately 10 milliseconds to approximately 30milliseconds.
 15. A method for controlling an electrical system having abackup PV power generation system, an energy storage system, and anenergy control system, the energy control system including a microgridinterconnection device electrically coupled to the backup PV powergeneration system, the energy storage system, a plurality of loads, anda utility grid, the method comprising: monitoring electronic data fromthe electrical system; determining whether the monitored electronic dataindicates a power deviation event; opening a PV disconnect device inresponse to determining the power deviation event to electricallydisconnect the backup PV power generation system from the microgridinterconnection device of the energy control system; and disconnecting,by the microgrid interconnection device, the utility grid from thebackup PV power generation system, the energy storage system, and theplurality of loads after opening the PV disconnect device, wherein thePV disconnect device is disposed electrically downstream from aninverter of the backup PV power generation system and electricallyupstream from the microgrid interconnection device, and wherein themicrogrid interconnection device electrically disconnects the utilitygrid from the backup PV power generation system and the energy storagesystem within a first response time range, and the PV disconnect deviceelectrically disconnects the backup PV power generation system from themicrogrid interconnection device within a second response time range,wherein the second response time range is less than the first responsetime range.
 16. The method of claim 15, wherein the step of determiningwhether the monitored electronic data indicates the power deviationevent further includes comparing a frequency of the power supplied bythe backup PV power generation system to a setpoint frequency.
 17. Themethod of claim 15, wherein the step of determining whether themonitored electronic data indicates the power deviation event furtherincludes detecting when an operating status of the utility gridindicates a power outage.